scholarly journals CORRIGENDUM FOR “Dapagliflozin Lowers Plasma Glucose Concentration and Improves β-Cell Function”

2017 ◽  
Vol 102 (12) ◽  
pp. 4662-4662
2015 ◽  
Vol 100 (5) ◽  
pp. 1927-1932 ◽  
Author(s):  
Aurora Merovci ◽  
Andrea Mari ◽  
Carolina Solis ◽  
Juan Xiong ◽  
Giuseppe Daniele ◽  
...  

Abstract Background: β-Cell dysfunction is a core defect in T2DM, and chronic, sustained hyperglycemia has been implicated in progressive β-cell failure, ie, glucotoxicity. The aim of the present study was to examine the effect of lowering the plasma glucose concentration with dapagliflozin, a glucosuric agent, on β-cell function in T2DM individuals. Research Design and Methods: Twenty-four subjects with T2DM received dapagliflozin (n = 16) or placebo (n = 8) for 2 weeks, and a 75-g oral glucose tolerance test (OGTT) and insulin clamp were performed before and after treatment. Plasma glucose, insulin, and C-peptide concentrations were measured during the OGTT. Results: Dapagliflozin significantly lowered both the fasting and 2-hour plasma glucose concentrations and the incremental area under the plasma glucose concentration curve (ΔG0–120) during OGTT by −33 ± 5 mg/dL, −73 ± 9 mg/dL, and −60 ± 12 mg/dL · min, respectively, compared to −13 ± 9, −33 ± 13, and −18 ± 9 reductions in placebo-treated subjects (both P < .01). The incremental area under the plasma C-peptide concentration curve tended to increase in dapagliflozin-treated subjects, whereas it did not change in placebo-treated subjects. Thus, ΔC-Pep0–120/ΔG0–120 increased significantly in dapagliflozin-treated subjects, whereas it did not change in placebo-treated subjects (0.019 ± 0.005 vs 0.002 ± 0.006; P < .01). Dapagliflozin significantly improved whole-body insulin sensitivity (insulin clamp). Thus, β-cell function, measured as ΔC-Pep0–120/ ΔG0–120 ÷ insulin resistance, increased by 2-fold (P < .01) in dapagliflozin-treated vs placebo-treated subjects. Conclusion: Lowering the plasma glucose concentration with dapagliflozin markedly improves β-cell function, providing strong support in man for the glucotoxic effect of hyperglycemia on β-cell function.


2000 ◽  
Vol 279 (3) ◽  
pp. E520-E528 ◽  
Author(s):  
Thomas Laedtke ◽  
Lise Kjems ◽  
Niels Pørksen ◽  
Ole Schmitz ◽  
Johannes Veldhuis ◽  
...  

Impaired insulin secretion in type 2 diabetes is characterized by decreased first-phase insulin secretion, an increased proinsulin-to-insulin molar ratio in plasma, abnormal pulsatile insulin release, and heightened disorderliness of insulin concentration profiles. In the present study, we tested the hypothesis that these abnormalities are at least partly reversed by a period of overnight suspension of β-cell secretory activity achieved by somatostatin infusion. Eleven patients with type 2 diabetes were studied twice after a randomly ordered overnight infusion of either somatostatin or saline with the plasma glucose concentration clamped at ∼8 mmol/l. Controls were studied twice after overnight saline infusions and then at a plasma glucose concentration of either 4 or 8 mmol/l. We report that in patients with type 2 diabetes, 1) as in nondiabetic humans, insulin is secreted in discrete insulin secretory bursts; 2) the frequency of pulsatile insulin secretion is normal; 3) the insulin pulse mass is diminished, leading to decreased insulin secretion, but this defect can be overcome acutely by β-cell rest with somatostatin; 4) the reported loss of orderliness of insulin secretion, attenuated first-phase insulin secretion, and elevated proinsulin-to-insulin molar ratio also respond favorably to overnight inhibition by somatostatin. The results of these clinical experiments suggest the conclusion that multiple parameters of abnormal insulin secretion in patients with type 2 diabetes mechanistically reflect cellular depletion of immediately secretable insulin that can be overcome by β-cell rest.


1999 ◽  
Vol 277 (2) ◽  
pp. E283-E290 ◽  
Author(s):  
Pankaj Shah ◽  
Ananda Basu ◽  
Rita Basu ◽  
Robert Rizza

People with type 2 diabetes have defects in both α- and β-cell function. To determine whether lack of suppression of glucagon causes hyperglycemia when insulin secretion is impaired but not when insulin secretion is intact, twenty nondiabetic subjects were studied on two occasions. On both occasions, a “prandial” glucose infusion was given over 5 h while endogenous hormone secretion was inhibited. Insulin was infused so as to mimic either a nondiabetic ( n = 10) or diabetic ( n = 10) postprandial profile. Glucagon was infused at a rate of 1.25 ng ⋅ kg−1 ⋅ min−1, beginning either at time zero to prevent a fall in glucagon (nonsuppressed study day) or at 2 h to create a transient fall in glucagon (suppressed study day). During the “diabetic” insulin profile, lack of glucagon suppression resulted in a marked increase ( P < 0.002) in both the peak glucose concentration (11.9 ± 0.4 vs. 8.9 ± 0.4 mmol/l) and the area above basal of glucose (927 ± 77 vs. 546 ± 112 mmol ⋅ l−1 ⋅ 6 h) because of impaired ( P < 0.001) suppression of glucose production. In contrast, during the “nondiabetic” insulin profile, lack of suppression of glucagon resulted in only a slight increase ( P< 0.02) in the peak glucose concentration (9.1 ± 0.4 vs. 8.4 ± 0.3 mmol/l) and the area above basal of glucose (654 ± 146 vs. 488 ± 118 mmol ⋅ l−1 ⋅ 6 h). Of interest, when glucagon was suppressed, glucose concentrations differed only minimally during the nondiabetic and diabetic insulin profiles. These data indicate that lack of suppression of glucagon can cause substantial hyperglycemia when insulin availability is limited, therefore implying that inhibitors of glucagon secretion and/or glucagon action are likely to be useful therapeutic agents in such individuals.


2016 ◽  
Vol 18 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Miranda M. Priya ◽  
Anandakumar Amutha ◽  
T.A. Pramodkumar ◽  
Harish Ranjani ◽  
Saravanan Jebarani ◽  
...  

BMC Nutrition ◽  
2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohammed Al Thani ◽  
Eman Sadoun ◽  
Angeliki Sofroniou ◽  
Amin Jayyousi ◽  
Khaled Ahmed Mohamed Baagar ◽  
...  

Abstract Background Vitamin D deficiency is associated with indicators of pre-diabetes including, insulin resistance, β-cell dysfunction and elevated plasma glucose with controversial findings from current trials. This study aims to investigate the long-term effect of vitamin D on glucose metabolism and insulin sensitivity in pre-diabetic and highly vitamin-deficient subjects. Methods One hundred thirty-two participants were randomized to 30,000 IU vitamin D weekly for 6 months. Participants underwent oral glucose tolerance test (OGTT) at 3-month intervals to determine the change in plasma glucose concentration at 2 h after 75 g OGTT (2hPCG). Secondary measurements included glycated hemoglobin, fasting plasma glucose and insulin, post-prandial insulin, indices of insulin sensitivity (HOMA-IR, Matsuda Index), β-cell function (HOMA-β, glucose and insulin area under the curve (AUC), disposition and insulinogenic indices), and lipid profile. Results A total of 57 (vitamin D) and 75 (placebo) subjects completed the study. Mean baseline serum 25(OH) D levels were 17.0 ng/ml and 14.9 ng/ml for placebo and vitamin D group, respectively. No significant differences were observed for 2hPC glucose or insulin sensitivity indices between groups. HOMA-β significantly decreased in the vitamin D group, while area under curve for glucose and insulin showed a significant reduction in β-cell function in both groups. Additionally, HOMA-β was found to be significantly different between control and treatment group and significance persisted after adjusting for confounding factors. Conclusion Vitamin D supplementation in a pre-diabetic and severely vitamin-deficient population had no effect on glucose tolerance or insulin sensitivity. The observed reduction in β-cell function in both placebo and vitamin D groups could be attributed to factors other than supplementation. Trial registration NCT02098980, 28/03/2014 (www.clinicaltrials.gov).


2011 ◽  
Vol 57 (4) ◽  
pp. 627-632 ◽  
Author(s):  
Barry R Johns ◽  
Fahim Abbasi ◽  
Gerald M Reaven

BACKGROUND Several surrogate estimates have been used to define relationships between insulin action and pancreatic β-cell function in healthy individuals. Because it is unclear how conclusions about insulin secretory function depend on specific estimates used, we evaluated the effect of different approaches to measurement of insulin action and secretion on observations of pancreatic β-cell function in individuals whose fasting plasma glucose (FPG) was &lt;7.0 mmol/L (126 mg/dL). METHODS We determined 2 indices of insulin secretion [homeostasis model assessment of β-cell function (HOMA-β) and daylong insulin response to mixed meals], insulin action [homeostasis model assessment of insulin resistance (HOMA-IR) and steady-state plasma glucose (SSPG) concentration during the insulin suppression test], and degree of glycemia [fasting plasma glucose (FPG) and daylong glucose response to mixed meals] in 285 individuals with FPG &lt;7.0 mmol/L. We compared the relationship between the 2 measures of insulin secretion as a function of the measures of insulin action and degree of glycemia. RESULTS Assessment of insulin secretion varied dramatically as a function of which of the 2 methods was used and which measure of insulin resistance or glycemia served as the independent variable. For example, the correlation between insulin secretion (HOMA-β) and insulin resistance varied from an r value of 0.74 (when HOMA-IR was used) to 0.22 (when SSPG concentration was used). CONCLUSIONS Conclusions about β-cell function in nondiabetic individuals depend on the measurements used to assess insulin action and insulin secretion. Viewing estimates of insulin secretion in relationship to measures of insulin resistance and/or degree of glycemia does not mean that an unequivocal measure of pancreatic β-cell function has been obtained.


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